Robust control for an uncertain LCL resonant ICPT system using LMI method

Frequency drift has considerable adverse effects on the inductively coupled power transfer (ICPT) system such as decrease of transmission power and distance, EMC interference, system detuning and performance deterioration, and deviated operation from system design requirements endangering the stability so that robust control of ICPT system remains an open applied research problem. This article presents a relevant uncertain model for the LCL resonant ICPT system first via the generalized state-space averaging and the LFT methods, and then a solution to H∞ controller synthesis by making use of the LMI method. The control design is first tested by computer simulation and thereafter verified by means of physical experiments. The results show that by applying the proposed H∞ synthesis controller the overall system has achieved both predetermined robustness with respect to the norm-bounded load and frequency uncertainties and dynamically tracking the voltage references according to the actual power demands.